1. Field of the Invention
This invention relates to a vehicle having systems to facilitate the transportation of loads as well as the vehicle itself. More particularly, the present invention relates to a vehicle having a suspension control system to avoid contact with surfaces, a support system for supporting the load carrying structure while enabling a limited degree of roll, yaw, pitch and side to side shifting, and a stowable operator's cab to lessen the width of the vehicle.
2. Background Discussion
(A) Suspension Control
The use of cargo transporters specifically suited for the movement of loads into and out of an airplane as well as storage within the airplane itself are known in the art as exemplified by U.S. Pat. No. 4,907,935. The prior art also recognizes the clearance problem associated with attempting to load such cargo transporters into and out of a cargo aircraft such as a C-130 cargo plane. For example, the above noted patent (U.S. Pat. No. 4,907,935) relies upon hydraulic means to vary the tilt of the transport loader in an attempt to avoid contact between the crest of the ramp surface and the understructure of the loader or contact between the upper surface of the loader and the roof of the plane's cargo hold.
U.S. Pat. Nos. 4,425,978 and 4,570,733 further illustrate rolling cargo containers having means to increase the distance between the wheels and the understructure of the cargo container so as to facilitate loading of the rolling cargo container onto the aircraft.
A common problem associated with the above cited prior art, lies in the heavy reliance on the operator to make the appropriate adjustments. In other words, the operator must have sufficient experience and familiarity with the vehicle to know when and to what extent the vehicle should be modified to ensure contact does not occur. Moreover, not only must the operator be experienced, the operator needs also to maintain a continuous watch over the situation. Such requirements on an operator can easily lead to inadvertent collision between an underlying or overlying surface of the cargo aircraft. Also, U.S. Pat. No. 4,907,935 avoids the use of an underlying base frame which, although perhaps providing added clearance in some areas, presents the potential problem of stability especially for higher weight loads.
U.S. Pat. No. 3,513,927 reveals a hydraulic system and motor designed to torsionally adjust wheel settings to accommodate for different terrain. The system relies upon the operator to determine what adjustments are to be made and to manipulate levers in the driver's cab to adjust the wheel setting. Hence, reliance is again placed on the operator's experience and reflexes.
U.S. Pat. No. 4,420,167 reveals a multi-wheel terrain vehicle having a hydraulic system for reducing the tipping movement of the vehicle. The hydraulic system is activated in accordance with level indicators provided by transducers positioned on rotating arms connected to the wheel and a gyro device positioned on the vehicle. This places great reliance on mechanical detection and the detection takes place coincident with the encountering of uneven terrain.
U.S. Pat. No. 4,618,156 features a vertical height control system using vertical height sensors and an inclination sensor to raise or lower the rear or front end of an automobile upon the automobile reaching an inclination such that the operator is placed in a more comfortable position.
U.S. Pat. Nos. 3,003,783; 4,518,169; 4,595,072; 4,770,438; 4,796,911 and 4,861,067 all disclose the use of ultrasonic emitters for detecting road conditions such that an active suspension system can be adjusted to provide the operator with a more comfortable ride. These devices generally harden or soften suspension devices by restricting or opening flow paths forming part of the suspension devices. Thus the devices are not concerned with monitoring clearance between the chassis of the vehicle and an underlying or overlying surface but, rather, with suspension adjustments to increase or decrease the damping ability of the suspension to accommodate the suspension for the handling of the sensed smooth or uneven road surface.
(B) Load Carrying Structure Support
The aforementioned U.S. Pat. No. 4,907,935 illustrates a frame and cargo platform combination elevated by hydraulicly activated linkage arms. Between the cargo platform and frame is positioned a plurality of hydraulic cylinders for tilting or raising the platform with respect to the frame. The platform can also be moved to the left or right with respect to the frame. The hydraulic cylinders are used for making adjustments in the position of the platform with respect to variable aircraft cargo deck positions. The arrangement however does not fulfill the requirements of (1) aligning a vehicle deck structure with respect to an aircraft's cargo hold and providing adequate freedom of movement while maintaining stability during all vehicle impacts including docking impacts and (2) reducing the maintenance requirements especially those concerning hydraulic fluid leakage.
U.S. Pat. No. 3,319,932 shows a pallet trailer with pivotable and elevatable linking arms. The uppermost end of each set of linking arms is connected to a transversely extending rod received within a spherical bearing assembly which is provided to accommodate platform roll. The driving means for elevating the platform can be disconnected at one or the other end to achieve a longitudinal tipping of the platform. In addition to the complexity and multitude of potentially breakable components, U.S. Pat. No. 3,319,932 fails to provide a desirable degree of freedom of movement while maintaining stability during all functions including docking impacts.
U.S. Pat. No. 3,743,044 illustrates a cargo aircraft having a suspension system for controlling vertical disposition as well as the roll and pitch of a supporting bed. The system features the use of a plurality of ball and socket connections. Similarly, U.S. Pat. No. 3,612,312 utilizes a hydraulic system in association with a ball and socket connection to achieve tilting of heavy structures such as prefabricated ship sections. These systems fail to provide the desired degree of freedom while still maintaining a relatively maintenance free system.
(C) Operator Cab Relocation
The cargo transporter noted in the aforementioned U.S. Pat. No. 4,907,935 illustrates an operator's cab which can be pivoted to the front of the transporter in order to reduce the width of the transporter in an aircraft hold. The pivoting of the cab, although reducing the width of the transporter, increases the length of the transporter thus reducing potential storage space in the aircraft cargo hold.
U.S. Pat. No. 3,489,300 illustrates a cargo handling apparatus which includes a driver's station moveable in a transverse direction into and out of a cutout formed in the load carrying bed. When the driver's station is positioned out of the cutout an opening is left wherein no conveyance rolling means is provided. This opening is problematic in the sense that shifting cargo might catch an edge of the cutout or cargo units might actually fall off through the cutout during transportation. Furthermore, the driver station moving means is positioned along the undersurface of the main support frame so as to reduce the clearance height between the main support frame and the ground below.
U.S. Pat. Nos. 3,944,277 and 4,250,975 further illustrate transverse driver station movement in the context of an automobile and a mining machine. U.S. Pat. No. 3,944,277 relies on an understation connection and an understation transverse force means location which lead to the above noted problems with clearance. U.S. Pat. No. 4,250,975 positions the transverse force means at a position behind the cab so as to require long hydraulic extension.